1. Field of the Invention
This invention relates to an apparatus and method for grinding and polishing spherical bodies such as single crystal silicon.
2. Description of the Related Art
Heretofore, a semiconductor device is formed according to the following method: That is, a circuit pattern is formed on a plate-shaped single crystal silicon wafer, and the wafer thus processed is subjected to dicing, to form a semiconductor chip. In this connection, recently a technique has been proposed in the art that a circuit pattern is formed on a spherical single crystal silicon body.
The spherical silicon body produced by the above-described technique must be exactly spherical. However, there has been only need for spherical semiconductor chips, and therefore a grinding and polishing apparatus available is only for silicon wafers; that is, an apparatus for grinding and polishing spherical single crystal silicon bodies are not available.
An example of a conventional spherical body grinding and polishing apparatus is an apparatus for manufacturing balls for pinball machines or bearings. Spherical silicon bodies must be considerably high in sphericity and must be mirror-finished with high accuracy, and are liable to be scratched and oxidized. With the apparatus, it is difficult to continuously a number of such spherical silicon bodies in an in-line system, and it is impossible to obtain spherical bodies high in sphericity.